Understanding the Statistics and Limitations of Large Database Analyses

*Department of Orthopaedic Surgery and †Department of Statistical Science, School of Advanced Sciences, the Graduate University for Advanced Studies, Tokyo, Japan. Address correspondence and reprint requests to Hiroyuki Yoshihara, MD, PhD, SUNY Downstate Medical Center, 450 Clarkson Ave, Brooklyn, NY 11203; E-mail: email protected Acknowledgment date: November 10, 2013. First revision date: March 16, 2014. Second revision date: March 19, 2014. Acceptance date: March 20, 2014. The Manuscript submitted does not contain information about medical device(s)/drug(s). No funds were received in support of this work. No relevant financial activities outside the submitted work.